Modified microcrystalline cellulose dispersion

ABSTRACT

A MODIFIED MICROCRYSTALLINE CELLULOSE IS OBTAINED BY THE INTERACTION OF MICROCRYSTALLINE CELLULOSE WITH GUARGUM IN AN AQUEOUS MEDIUM. THIS MODIFIED MICROCRYSTALLINE CELLULOSE FUNCTIONS SIMULTANEOUSLY AS A BODY ENHANCER, CLOUDIFIER AND SUSPENDING AGENT IN ACIDIC SOFT DRINKS AND PREVENTS THE SETTING OF THE PULP PARTICULES PRESENT IN THE SOFT DRINKS AND/OR THE FORMATION OF THE &#34;RING&#34; IN THE UPPER LAYER OF THE DRINKS.

3,827,899 Patented Aug. 6, 1974 United States PatentOffice Iut Cl. cosh 25/00, 27/18 U.S-. onion- 20s.

4 Claims I 'BSTR" cT oF- ruE-DIscLosURE I mod fied microcrystalline cellulose is obtained by the,interaction of microci'ystallinecellulose with guarguni in an.atiueouslmedium.'Thismodified microcrystalline cellulose functio'ris simultaneously as. a body enhancer, cloudifierand suspen 'iaga em cidic soft drinks and preventsf'the" settling of ;the..piilpp il 1es present in the soft drinks and/onfheformatiori'of the ring in the upper layer of the drinks. 7

This invention relates,.to a new additive to be used for-the; stabilization of the suspension in soft drinks.

Stabilizerspare used in various branches of the food industry toprevent the occurrence ofundesirable changes. Though theinvention is applicable-in principle to all nds i9f,; d ink t. i o pe ia importance in gard;t o acidiosoft drinksand mainly to those acidic softdrinks which contains-pulpparticles such as juice (citrus, .tomatoes 'etc.,).; j w,

The, term .fsoft drinks? embraces syrups, carbonated beverages .andstill beverages-Th lcarbonated beverages being either flavored with sugar, es sence and acid or unfiavored containing carbon dioxide and minerals. The still beverage may either 'be'friuf'jiiice with'or without added sugar and water of it'may contain flavoring material, sugar and acid proportioned"with water.

The 'composition and "stabilityof-"the colloidally disperse'cl 'materials in soft-*drinks aifeet considerably the quality of the products. The reason is that these ma.- terial'si 'contribute to the' flavor, color appearance and teirtu're of the bevera'gez From flthe standpoint bf appearance, one of the undesirable" features of juicecontaining suspended solids is "the tendency' of the solid to settle during storage. This is particualrly noticeable in juice packed in glass, but it maymot be evident .,to the. fililsuuier although it exists when juice is packed in. can s.]This is the result jth ns abili ust.saspsn d l 'd la the emulsible I n drink w clrcontains more pulp ring at the op of-"the bottle. d it s -t is k es; banned the use of these potential in rting flavor 'ljhe precipitation will a; fe s ta on "colloidal instability is the the soft drinks infor instance erm lsions, e conventional clouding r, n the last ,years the food safetyi hea th h z d t d-fi as al g inatesfjcarcarboxymethyl v which would prevent the sedimentation of the pulp in cellulose or various types of starches have been used as body enhancers .suspending agents. However, although they were found to be effective in increasing the viscosity of the soft drink, their capacity to retard the sedimentation of suspended pulp is limited.

Thus it was long felt desirable to find an additive acidic soft drinks in obtaining a homogenized drink.

The present invention has the object to provide a new additive for preventing the precipitation of the pulp in acidic soft drinks.

It is another object of the present invention to provide an additive which. fulfills in addition to prevention of the precipitation of the solids in acidic soft drinks, the

purposes of other additives for soft drinks such as body enhancer and cloudifier.

The invention therefore, consists of a modified microcrystalline cellulose dispersion prepared by the interaction of microcrystalline cellulose and guar-gurn in an aqueous medium characterized by its outstanding stability in acidic soft drinks. The term guar-gum includes also fractions of guar-gum. The new additive was found to be 'very useful in the stabilization of suspensions in acidic soft drinks, preventing the settling of the pulp particles and/or formation of a ring in the upper layer of soft drinks.

Microcrystalline cellulose has been suggested as a clouding agent for a beverage prepared in a powder form.

But its dispersibility and stability in acidic soft drinks is quite poor. Also guar-gum alone or other fractons of this gum used in food industries were tried with a rather limited success to accomplish this function of preventing the settling of the pulp. Thus, it has now been unexpectedly found that the modified microcrystalline cellulose dispersion can successfully prevent the settling I ofpulp, and simultaneously fulfill the functions of body enhancer and coludifier required for soft drinks. This preand a similaiztyiseosity; is not.,,suitable.- for the preparatio an were The; 'prepara-tion of the 1 modified ,-miorocrystal1ine cellos; lose is every-simple the-microcrystallinecellulo'se sand guar gumeare dispersed in neutral nor. slightlysasalkaline water.Ittisipreferable to incorporate inathesolid micro-'" crystalline cellulose a dispersing agent such as carboxyvention of settling the pulp occurs only when the modified microcrystalline cellulose dispersion is prepared prior to its addition to the soft drink. By adding separately the mcirocrystalline and guar-gum directly to the soft'drink, no interaction between the components occurs and no stabilization effect of the suspension is obtained.

The modified microcrystalline dispersion is. the result of the interaction of the two ingredients, microcrystalline cellulose or .guar-gum in development of a different property which is not possessed by the two ingredients taken separately. The eiiactstructure of the modified microcrystalline cellulose is unknown. It seems that the interaction between the microcrystalline cellulose and guar-gum takes place by a sort of cross-linking in resulting a new colloidalstructurer J The term guar-gum includes also fractions of this gum having molecular weight as expressed by its viscosity in the range of 2800 to 69,00Q ops. It was surprisingly found that other, types of food grade, gums arenot suitable fpr L thispreparation; since the,microcrystalline.cellulose does not interact with the gum, to forrna stable ,suspension.in

acidic media. Thus,v for example, locust bean gum, which like s rzsu i a so a a s t man n an s pthar hydrophilic Dids.with.,-very;, similan properties-in solutio of the-modified microcryst-allinecellulose.

methyl cellulose to render the cellulose more dispersible in aqueous systems. The suspension' is vigorouslymixed by 'thuse of a shearing device suchfasf-Waring Bleii'do The amount of guar-gum which -interacts with the microcrystalline cellulose in obtaining the modified microcrystalline cellulose is not critical. The preferable amount is between the range of 1 part guar-gum, to 0.5 parts, to 12 parts of microcrystalline cellulose. Generally a modified microcrystalline cellulose containing smaller amounts of guar-gum will effectively stabilize the suspension when no fruit pulp is present in the system and when the system does not undergo pasteurization and is stored under refrigeration. However, fruit juices consist of considerable quantities of finely divided suspended fruit solids. The amount of suspended solids varies according to the fruit; for instance it is between 713% (volume) for orange juice and 35-11% (volume) for grapefruit juice. In these cases, the modified microcrystalline cellulose is preferred to contain at least 25% of guar-gum.

With citrus syrups (20 Brix) designed for home use normally an unpleasant phenomenon of a ring formation in the upper layer occurs. This ring contains actually the main components of the flavor. It was found that by using the modified microcrystalline cellulose obtained according to the present invention the formation of this ring is prevented.

The preparation of the modified microcrystalline cellulose is done at ambient temperature. In some cases such as concentrated juices, higher temperatures than the ambient might be desirable.

The modified microcrystalline cellulose has properties which cannot be accounted for by the additive contribution of its two components. One of the tests which proves this fact is filtration. The filtration test is illustrated in Table I where the filtration rates of a solution of 0.25% microcrystalline cellulose and of a solution of 0.25 modified microcrystalline cellulose are given. The filtration was done on the same aliquot of ml. of dispersion through a qualitative Whatman No. 1 filter paper having a filtration area of 4.5 cm. The filtration was carried out at ambient temperature (25 C.) under a pressure gradient of 715 mm. Hg (achieved by a vacuum pump) TABLE I Filtration rate of Filtration rate of 0.25% 0.26% modified microcrystalline cellulose microcrystalline dispersion cellulose dispersion Filtration Filtra- Filtravolume, tion time, tion time, ml. min. min.

used in the preparation of the'modified microcrystalline cellulose has a negligible resistance'to flow: 10 ml. of a 0.05% guar-gum'dispersion were obtained as filtrate in l5seconds.

Another physical test which shows the difference of. the

crystalline cellulose and'modified microcrystalline cellulose dispersions.

From the above values it is evident that a build-up of structure occurs in the resulting stored system containing microcrystalline cellulose interacted with guar-gum.

This phenomenon known as thixotropy proves also that the interaction which occurred between the microcrystalline cellulose and guar-gum by a sort of cross-link ng, im

poses an array of a characteristic colloidal system. I

It seems that due to these improved physical properties of the modified microcrystalline cellulose this material is successful in the stabilization of the suspension in the soft drinks.

The microcrystalline cellulose may be used in its pure state or preferably in its commercial form known under the trademark Avicel-RC-581" produced by FMC Corporation (Philadelphia, U.S.A.). This material contains 89 parts by weight of microcrystalline cellulose and 11 parts of sodium carboxymethyl cellulose. The sodium car'- boxymethyl cellulose is normally required as a dispersant additive but it does not interact with the microcrystalline cellulose to stabilize acidic systems. It was also found that the addition of quantities of carboxymethyl cellulose ranging from 10-200%- on the basis of Avicel-RC-581 did not stabilize the suspension at low pH values. The use of the modified microcrcystalline cellulose in soft drinks v has several advantages. Among them are: j

(1) All the components used in the modified microcrystal- 3 line cellulose are known and permitted to be incorpo rated in the food industry.

(2) The modified microcrystalline cellulose functions simultaneously as a body enhancer, cloudifier and suspending agent. (3) The combination of these three functions is quite unique and very useful in the soft drinks and especially in those containing large amounts of pulp (orange juice,

grapefruit juice, tomato juice) where the function of prevention of the sedimentation of the pulp is very important.

The following is a general modified microcrystalline cellulose:

The aqueous dispersion of modified microcrystalline" cellulose is mixed with the soft drink i.e. sugar-acid solution, juice etc. The amount of' modified microcrystalline I cellulose required for acidic soft drink to prevent settling is at least 0.02% wt. percent. Preferably this amount is between 0.05% to 0.75%. After that it is preferable to shear the mixture using a Waring Blender or a sonicator.

The final system may be pasteurized andthen stored at ambient temperature or under refrigeration. The pH of the product may be as low as 2 and the'stability of the system is not impaired by the acidic conditions characteristic to soft drinks and. juices. The suspensionwas stable and the system was homogeneous without precipitation" of the pulp even after six months of. storage at 1-4 C.

The modified microcrystalline cellulose was found to be successfully used for acidic soft drinks including syrups and juices where more pulpis present and the .problem of the stabilization of suspension is more evident.

When juices such as orange juice are addedto the syse tem it should be first pasteurized and sheared sinceother wise .the stability of the products will.be impaired.

When juice concentrates such as orange juice concenw trates are added to the system they may be either reconcem' description of the useof the trated prior to incorporating them in the product or added as concentrates.

The invention is illlstrated by the following examples to which it is not limited.

EXAMPLE 1 80 mg. guar-gum (trademark Meyprogat 90) and 250 mg. microcrystalline cellulose were dispersed in 50 ml. of tap water in the presence of 30 mg. of sodium carboxymethyl cellulose by shearing for 5 minutes in a Waring Blender at 25-35 C.

To the above dispersion 17 ml. of sucrose-citrate buffer (containing 20% sucrose and 6% citrate) and 33 ml. of grapefruit juice and orange juice were then added. The samples were pasteurized in 20 x 150 mm. test tubes by heating for 12 minutes at 70 C. and then storing at 30 C. After a three-months storage, the phase containing the mixture of juice pulp and modified microcrystalline particles occupied 97% of the total volume of the samples.

In blanks not containing the modified microcrystalline cellulose, sedimentation of fruit pulp to the bottom of the test tubes occurred after a few days. In blanks containing the regular microcrystalline cellulose, the lower phase containing the suspended particles occupied only 50% of the total volume, after a one week storage at 30 C.

EXAMPLE 2 Two batches of 50 mg. of guar-gum (trademark Meyprogat 90) and 250 mg. microcrystalline cellulose were dispersed in the presence of 30 mg. of carboxymethyl cellulose in 50 ml. of tap water by shearing for minutes in a Waring Blender at 25-35 C.

To each one of the above dispersion 17 ml. of sucrosecitrate buffer pH 3.25 and 33 ml. of Schweppes Bitter Lemon (Iafora Ltd., Rehovot, Israel) and Schweppes Golden Orange (Jafora Ltd, Rehovot, Israel) were then added.

The samples were stored at 1-4 C. The phase containing the suspended particles occupied 90-98% of the total volume even after a three months storage.

EXAMPLE 3 5 g. of microcrystalline cellulose and 1.485 g. guar-gurn (trademark Meyprogat 90) were dispersed in 100 ml. H O in a Waring Blender for 5 minutes in the presence of 0.5 g. sodium carboxymethyl cellulose. The mixture was heated to about 80 C. for ten minutes.

50 g. of orange concentrate (60 B'rix) were mixed with 50 g. of the above modified microcrystalline cellulose. The paste was diluted with 450 ml. water and the diluted suspension was heated to 85 C. and then cooled to ambient temperature. The suspension was then mixed with an equal volume of sucrose-citrate buffer pH 3.25 (containing 1.5% citrate and 5% sucrose). The final dispersion was sheared in a Waring Blender for 3 minutes and then pasteurized (see Example 1). It was stable on storage at ambient temperature, for three months.

EXAMPLE 4 (The preparation of the dispersion was done at 25- 30 C.). 250 mg. Avicel RC-581 and 50 mg. guar-gum (Meyprogat 90) were dispersed in 75 ml. water by shearing for five minutes in a Waring Blender. 25 ml. of a sucrose-citrate buffer, pH 3.25 (containing 21% sucrose and 6% citrate) were then added. The suspension was stable even after a six month storage under refrigeration. When the amount of guar-gum dispersed with the Avicel was reduced to 20 mg. (per 100 ml. final product) the suspension was stable for two months under refrigeration while in systems not containing guar-gum but only Avicel flocculation and precipitation occurred immediately on adding the citrate.

EXAMPLE 5 200 mg. guar-gum (trademark Meyprogat 90) and 500 mg. Avicel RC 581 were dispersed in 50 ml. water by shearing in a Waring Blender for 5 minutes at ambient temperature (ZS-30 C.). 17 mls. of a sucrose-citrate buffer pH 3.2 (containing 20% sucrose and 6% citrate) were then added, followed by 133 ml. of a freshly extracted tomato juice (the tomatoes were heated to about 80 C. prior to extracting them). The volume was made up to 200 ml. and the solution was then sheared for 3 minutes in a Waring Blender. Samples were pasteurized for 12 minutes at C. The suspension was stable after a two-months storage at ambient temperature (20-30 C.). On the other hand, in blanks not containing the modified microcrystalline cellulose, precipitation of suspended particles commenced after 2-3 days.

EXAMPLE 6 250 mg. of microcrystalline cellulose and 70 mg. guargum (trademark Meyprogat 90) were dispersed in ml. tap water by shearing in a Waring Blender for 5 minutes at ambient temperature (ZS-30 C.). To this dispersion, 25 ml. of a sucrose-citrate buffer pH 3.2 (containing 20% sucrose and 6% citrate) were added. The suspension was quite stable. In a blank experiment not containing the modified microcrystalline cellulose, but only the normal microcrystalline cellulose, precipitation of cellulose occurred on adding the acidic buffer solution.

I claim:

1. A modified microcrystalline cellulose dispersion consisting essentially of the interaction product prepared by the interaction of 1 part by Weight guar gum and 0.5 parts to 12 parts by weight microcrystalline cellulose.

2. A modified microcrystalline cellulose dispersion according to claim 1 which also contains sodium cal-boxymethyl cellulose.

3. A dispersion in accordance with claim 1 formed in a neutral or slightly alkaline aqueous medium and vigorously mixed in a shearing device and wherein said guar gum has a viscosity of 2800 to 69,000 cps.

4. A modified microcrystalline cellulose dispersion according to claim 1 to be used in acidic soft drinks as suspending agent, body enhancer and cloudifier.

References Cited UNITED STATES PATENTS 3,440,065 4/ 1969 La Via 106-209 X THEODORE MORRIS, Primary Examiner U.S. Cl. X.R. 106.204, 209 

